/**
 * Software License, Version 1.0
 * 
 * Copyright 2003 The Trustees of Indiana University. All rights reserved.
 * 
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 * 
 * 1) All redistributions of source code must retain the above copyright notice,
 * the list of authors in the original source code, this list of conditions and
 * the disclaimer listed in this license; 2) All redistributions in binary form
 * must reproduce the above copyright notice, this list of conditions and the
 * disclaimer listed in this license in the documentation and/or other materials
 * provided with the distribution; 3) Any documentation included with all
 * redistributions must include the following acknowledgement:
 * 
 * "This product includes software developed by the Community Grids Lab. For
 * further information contact the Community Grids Lab at
 * http://communitygrids.iu.edu/."
 * 
 * Alternatively, this acknowledgement may appear in the software itself, and
 * wherever such third-party acknowledgments normally appear.
 * 
 * 4) The name Indiana University or Community Grids Lab or NaradaBrokering,
 * shall not be used to endorse or promote products derived from this software
 * without prior written permission from Indiana University. For written
 * permission, please contact the Advanced Research and Technology Institute
 * ("ARTI") at 351 West 10th Street, Indianapolis, Indiana 46202. 5) Products
 * derived from this software may not be called NaradaBrokering, nor may Indiana
 * University or Community Grids Lab or NaradaBrokering appear in their name,
 * without prior written permission of ARTI.
 * 
 * 
 * Indiana University provides no reassurances that the source code provided
 * does not infringe the patent or any other intellectual property rights of any
 * other entity. Indiana University disclaims any liability to any recipient for
 * claims brought by any other entity based on infringement of intellectual
 * property rights or otherwise.
 * 
 * LICENSEE UNDERSTANDS THAT SOFTWARE IS PROVIDED "AS IS" FOR WHICH NO
 * WARRANTIES AS TO CAPABILITIES OR ACCURACY ARE MADE. INDIANA UNIVERSITY GIVES
 * NO WARRANTIES AND MAKES NO REPRESENTATION THAT SOFTWARE IS FREE OF
 * INFRINGEMENT OF THIRD PARTY PATENT, COPYRIGHT, OR OTHER PROPRIETARY RIGHTS.
 * INDIANA UNIVERSITY MAKES NO WARRANTIES THAT SOFTWARE IS FREE FROM "BUGS",
 * "VIRUSES", "TROJAN HORSES", "TRAP DOORS", "WORMS", OR OTHER HARMFUL CODE.
 * LICENSEE ASSUMES THE ENTIRE RISK AS TO THE PERFORMANCE OF SOFTWARE AND/OR
 * ASSOCIATED MATERIALS, AND TO THE PERFORMANCE AND VALIDITY OF INFORMATION
 * GENERATED USING SOFTWARE.
 */
package cgl.narada.matching.string;

import java.util.Hashtable;

import cgl.narada.event.NBEvent;
import cgl.narada.event.TemplateProfileAndSynopsisTypes;
import cgl.narada.matching.MatchingTree;
import cgl.narada.matching.Profile;
import cgl.narada.matching.ProfileCounts;
import cgl.narada.protocol.Destinations;
import cgl.narada.protocol.ProfilePropagationProtocol;

/**
 * This class implements the STRING matching algorithm. This provides methods to
 * add a subscription and also to remove interest in a subscription predicate.
 * The matching algorithm should also be able to compute destinations.
 * 
 * @author Shrideep Pallickara $Revision$ $Date$
 */

public class StringMatching implements MatchingTree, StringMatchingDebugFlags {
   /** Profile Propagation Handler */
   private ProfilePropagationProtocol profilePropagationProtocol;

   /** The unit level for this matching tree */
   private int unitLevel;

   /** The system level */
   private int systemLevel;

   /** The destination for this node */
   Destinations thisDestination;

   private Hashtable profilesAndDestinations, profileIds;

  
   private String moduleName = "StringMatching: ";

   /** The StringMatching constructor */
   public StringMatching(int unitLevel, int systemLevel,
         ProfilePropagationProtocol profilePropagationProtocol) {
      this.unitLevel = unitLevel;
      this.systemLevel = systemLevel;
      this.profilePropagationProtocol = profilePropagationProtocol;
      profilesAndDestinations = new Hashtable();
      profileIds = new Hashtable();

   }

   /**
    * This method returns the level assocaited with this matching tree. A node
    * could be a gateway at multiple levels. How it handles destinations at
    * different levels, and propagates destinations at different levels is
    * dicatated by the level of the matching tree which computes the
    * destinations and initiates profile propagation changes.
    * 
    * @return The level of the matching tree.
    */
   public int getMatchingLevel() {
      return unitLevel;
   }

   /** This method sets the destination address for this node */
   public void setNodeDestination(Destinations destination) {
      thisDestination = destination;
   }

   /**
    * This method adds a subscription predicate to the matching tree
    * 
    * @param profile
    *           The predicate comprising the subscription and the destination
    *           assocaited with the subscription.
    */
   public void addSubscriptionProfile(Profile profile) {
      StringProfile stringProfile = (StringProfile) profile;
      String profileId = stringProfile.getProfileId();
      if (profileId == null) {
         System.out.println(moduleName + "Profile Id is NULL in profile "
                            + profile);
         return;
      }

      if (profileIds.containsKey(profileId)) {
         if (StringMatching_Debug) {
            System.out.println(moduleName + "Profile " + profile
                  + " has already been added ");
         }
         return;
      }
      
      if (StringMatching_Debug) {
         String report = moduleName + "Adding Profile " + profile
         + "   : at unit level" + unitLevel;
         System.out.println(report);
      }

      profileIds.put(profileId, profile);
      /**
       * add the id to list of id's being maintained
       */
      ProfileCounts _profileCounts;
      Object _subscription = stringProfile.getSubscription();

      /**
       * Each subscription has a list of destinations and counts/destination
       * associated with it. If this subscription already exists, update profile
       * counts associated with the entry. Otherwise, simply create a new entry
       */
      if (profilesAndDestinations.containsKey(_subscription)) {
         _profileCounts = (ProfileCounts) profilesAndDestinations
                                                                 .get(_subscription);
      } else {
         if (StringMatching_Debug) {
            System.out.println(moduleName + "Creating new ProfileCounts for "
                               + "subscription = " + _subscription);
         }
         _profileCounts = new ProfileCounts();
         profilesAndDestinations.put(_subscription, _profileCounts);
      }
      _profileCounts
                    .incrementCountForDestination(stringProfile
                                                               .getDestination());
      if (StringMatching_Debug) {
         System.out.println(moduleName + "Added profile " + profile);
      }/* end debug */
   }

   /**
    * This method removes a subscription predicate to the matching tree
    * 
    * @param profile
    *           The predicate comprising the subscription and the destination
    *           assocaited with the subscription.
    */
   public void removeSubscriptionProfile(Profile profile) {
      StringProfile stringProfile = (StringProfile) profile;

      String profileId = stringProfile.getProfileId();
      if (profileId == null) {
         System.out.println(moduleName + "Profile Id is NULL in profile "
                            + profile);
         return;
      }

      if (!profileIds.containsKey(profileId)) {
         System.out.println(moduleName + "Profile " + profile
                            + " is not listed here");
         return;
      }

      profileIds.remove(profileId);
      /**
       * remove id from list of id's being maintained
       */
      if (StringMatching_Debug) {
         System.out.println(moduleName + "Profile ["
                            + stringProfile.getProfileId() + "] removed");
      }/* debug */

      Object _subscription = stringProfile.getSubscription();
      /**
       * Each subscription has a list of destinations and counts/destination
       * associated with it. Update destinations associated with subscription.
       * If destinations has reduced to zero remove the entry.
       */
      ProfileCounts _profileCounts = (ProfileCounts) profilesAndDestinations
                                                                            .get(_subscription);
      boolean delete = false;
      delete = _profileCounts
                             .decrementCountForDestination(stringProfile
                                                                        .getDestination());
      if (delete) {
         profilesAndDestinations.remove(_subscription);
         if (StringMatching_Debug) {
            System.out.println(moduleName + "Entry [" + profile + "] removed");
         }/* debug */
      }
   }

   public void propagateChangesToHigherLevels(Profile profile,
                                              boolean addProfile) {
      StringProfile stringProfile = (StringProfile) profile;
      /**
       * The first step ofcourse is to replace lower level destinations with the
       * destination ID at the next higher level
       */
      if (StringMatching_Debug) {
         System.out.println("The destination associated with predicate "
                            + stringProfile.getSubscription() + " is "
                            + stringProfile.getDestination());
      }

      int temp = unitLevel;
      int tempDest;
      for (; temp < systemLevel;) {
         tempDest = thisDestination.getDestinationsAtLevel(temp);
         if (StringMatching_Debug) {
            System.out.print("This destination would be replaced by "
                             + tempDest);
         }
         temp++;
         if (StringMatching_Debug) {
            System.out.println(" for representation in a level(" + temp
                               + ") tree ");
         }

         StringProfile _propagateProfile = new StringProfile(
                                                             (String) stringProfile
                                                                                   .getSubscription(),
                                                             tempDest,
                                                             stringProfile
                                                                          .getProfileId());

         profilePropagationProtocol.propagateProfileChange(_propagateProfile,
               temp, addProfile);
      }
   }

   /**
    * This method return the destinations assocaited with an event that needs to
    * be matched to the matching tree
    * 
    * @return The destination as an INT
    */
   public Object matchEvent(NBEvent nbEvent) {
      Object stringKey = nbEvent.getContentSynopsis();
      if (profilesAndDestinations.containsKey(stringKey)) {
         ProfileCounts _profileCounts = (ProfileCounts) profilesAndDestinations
                                                                               .get(stringKey);
         return new Integer(_profileCounts.getDestinations());

      }
      if (StringMatching_Debug)
         System.out.println(moduleName + "Event doesn't have any matching "
                            + "destinations");
      return new Integer(0);
   }

   /** Returns the type of profiles managed by this matching engine */
   public int getManagedProfileType() {
      return TemplateProfileAndSynopsisTypes.STRING;
   }

   public static void main(String[] args) {

   }

}
